This invention relates to a converter for allowing standard polyvinyl chloride (PVC) pipe to be used as the pipe in a calliope. This invention further relates to a musical instrument assembly made with that converter and a method of making a musical instrument assembly with such a converter. Various musical instruments have used pipes to generate notes. In particular, the frequency of the note has depended upon the resonance established within air inside of a pipe or tube. Among such instruments have been pipe organs and calliopes.
In a pipe organ, a note is established by pressurized air supplied to one of numerous pipes, each of which generally corresponds to a single note. An opening, which usually covers only a small portion of the circumference of the pipe, allows sound to escape from the pipe. It is difficult to control the sound of the note from the pipes of a pipe organ. Increasing or decreasing the pressure of the air supplied to the pipe may change the volume, but it will also change the note which is produced. To control the volume, wooden louvers have sometimes been used.
Calliope pipes have an opening or mouthpiece which essentially extends around 360.degree. of the pipe. Such structures usually have a tube in which a resonance is established. The tube has a plug inside to close off one end. The opposite end of the tube has a mouthpiece mounted thereon. The mouthpiece has a series of offset members which are mounted to the outside of the tube. The mouthpiece has a disc therein and openings extended around the disc such that pressurized air may flow out through the openings and strike a beveled edge of the tube, which establishes the resonance between the disc of the mouthpiece and the plug within the tube. The opening between the beveled edge of the tube and the disc of the mouthpiece essentially extends around 360.degree. with the exception of very small portions at which the offset members are disposed. This allows one to change the volume by changing the air pressure as such changes in air pressure will be much less likely to significantly affect the frequency of the note than in the case of a pipe organ pipe.
Although one can adjust the volume of a calliope by adjusting the pressure of the air supplied to it, a calliope typically has a large number of pipes. Adjusting the air pressure at the source will change the volume of all of the notes. In other words, it has been impossible or difficult to individually adjust the volume of the different pipes within a calliope.
Assembling a calliope has typically required one to weld or otherwise secure offset members of a metallic mouthpiece to a metallic tube. The tube length must be accurately controlled in order to provide the desired note. Upon having a tube of the correct length, one must then make a beveled edge at the mouthpiece end of the tube. The need to make a beveled edge in a tube of the proper length increases the difficulty in making a calliope.